Accurion EP4 - Imaging Ellipsometer

Overview

The EP4, Park System's latest generation of imaging ellipsometers, combines ellipsometry and microscopy. This enables the characterization of thickness and refractive index with the sensitivity of ellipsometry on micro-structures as small as 1 µm. The microscopic part enables a simultaneous measurement of all structures inside the field of view of the optical system. Conventional ellipsometers have to focus on the measurement spot, while not achieving comparable lateral resolution, and measure spot by spot.

The microscopic part of the EP4 enables an ellipsometric-enhanced contrast for microscopic images obtained. Minor changes in refractive index or thickness can be seen in the live view of the camera. This allows to identify regions of interest for the ellipsometric measurements to obtain values for thickness (0.1 nm - 10 µm) and refractive index. 3D maps of the lateral variation of thickness and/or refractive index can be recorded within a single measurement.

Combination with complementary methods, e.g. AFM, QCM-D, reflectometry, Raman, is available to allow the observation of the same area. Further accessories may expand measurement possibilities under controlled ambient conditions or temperature changes.

Sophisticated Modeling Software

The modular EP4 software allows direct control and parallel or offline analysis. The EP4 control operates the instrument. Regions for measurements can be selected in the live view. Multiple samples can be arranged and measured automatically. The DataStudio enables data processing of the recorded data. Histogram analysis and line profiles offer a great insight into the details for your samples. The EP4 Model allows the modeling of the samples. Its intuitive handling concept helps the user to create simple to complex sample structures of thin films. It yields information on thickness and refractive indices of the sample. Further physical parameters, e.g. Bandgap or Volume Fraction of a mixed material layer can be obtained as well.

Key Features

• Modular setup: Easy upgrades between different configurations from BAM, single wave-, multiwave- to full spectroscopic ellipsometer
• Spectroscopic imaging ellipsometry from 190/250/360 nm to 1000/1700/2700 nm
• Highest lateral ellipsometric resolution of 1 µm, allowing to determine thickness and refractive index on microstructures as small as 1 µm
• Ellipsometric enhanced contrast images for a live visualization of the sample
• First identify, then measure: Intuitive selection of measurement region by drawing region in live view
• Parallel measurement of multiple regions within the selected field of view
• Patented knife-edge illumination for the non-destructive suppression of disturbing backside-reflections
• Enlarge your measurement possibilities by using additional accessories, e.g. cells, temperature control or liquid handling
• Quality Control: Also available as OEM version for QC in product lines

Technology

Imaging Ellipsometry (IE)

Accurion’s Imaging Ellipsometers combine the benefits of ellipsometry and optical microscopy in a single device. The unification of the two technologies creates a unique metrology tool that redefines the limits of both ellipsometric measurements and polarization-contrast microscopy. The enhanced spatial resolution of imaging ellipsometers (about 1 µm) expands ellipsometry into new areas of microanalysis, microelectronics, and bio analytics.

Imaging Ellipsometry in a Nutshell

• Imaging Ellipsometry is an all-optical, non-contact metrology technique that excels at the layer-thickness and material characterization of micro-structured thin-film samples and substrates.
• The technique combines microscope imaging with the measurement principles of spectroscopic ellipsometry. It reaches a spatial resolution of about 1 µm, easily beating the limits of other optical metrology tools such as regular ellipsometers or reflectometers.
• The measurement is based on the sample’s interaction with polarized light. By means of computational modeling, the measured polarization properties translate into maps of the physical sample properties like layer thickness, refractive index and absorption, roughness or anisotropy.

Applications

• 2D-Materials
• Curved Surfaces
• Transparent Substrate
• Surface Engineering
• Air-Water Interface
• Anisotropic Films
• Bio Interfaces
• MEMS
• Photonics
• Displays
• Battery Materials